I would love to find a way to get people "liking" problems more often. Liking makes the author feel good about a job well done, but more importantly it points people to good problems. Sometimes we try to motivate people to like problems. This happened with the October triathlon contest (when the problem you reference was created). But it can have an unintended outcome of encouraging people to like problems that aren't that great. The results are very uneven. Bottom line: if you like a problem, please "like" it!